Brushless motor's for micro's ?

[Andris Golts]

Hi all been doing more reading on the forum's on brushless motors now besides knowing a tiny bit about inrunners and outrunner's different kv ratings came across something called poles from what i understand the more pole's the more torque the motor makes correct me if im wrong. For micro hydro set up like mine where battery hull and all gear should come around just 22 oz . Would there be an advantage of me using a 6 pole motor over a 2 pole motor ? Also going to different sites that sell motors noticed different pricing .Which brands are good quality ?Regards Andris Golts.

[SweetAccord]

In-runners are more RPM based in comparison to out-runners that are more torque based.

The number of motor poles can be increased to gain some improvement in motor torque. There are more conductors, resulting in more current that the rotor may accept. An increased number of poles will also produce a stronger magnetic field.

For example, a 2-pole stator of 80-mm diameter and 90-mm length will output around 1.7 Nm torque; a 4-pole motor will output 2.3 N-m torque. A 6-pole motor in the same size would have about 2.8 N-m torque. While higher motor torque can be achieved by using a motor with a greater number of poles, this requires a higher output frequency to run at similar speeds.

A 4 or 6 pole motor is more forgiving than a 2 pole when accidentally over propped. The current surges are not as high.

As for sites for motors, OSE has a good selection of motors. All are good quality or Steve would not carry them.

Hope that helps.

[sailr]

We now have some of the new Tenshock 4 pole motors in stock. Not on the website yet. These are setting the world on fire in Europe!

[FRED]

SweetAccord; higher the # of poles, the more juice is needed to run them, correct.

[SweetAccord]

SweetAccord; higher the # of poles, the more juice is needed to run them, correct.

More poles is more torque, hence; for the same given motor: High Kv - needs more Current and Low Kv - needs more Voltage.

[Andris Golts]

Thanks to all for the great information. Regards Andris Golts.

[monojeff]

What you guys think of the 3000kv water cooled motor?
http://www.hobbypartz.com/88e-ads-30...ool-motor.html

I am thinking about running it in a 17" ABS mini hydro I have.

I was going to run a 4800kv motor http://www.hobbypartz.com/07e-c-sl-12t-2040-blue.html
but figured the 3000kv would be a little better
going to run it with a hobbywing 35amp esc any thoughts?

[Jeff Wohlt]

Higher pole counts are usually also easier on ESCs as well.

[sundog]

What you guys think of the 3000kv water cooled motor?
http://www.hobbypartz.com/88e-ads-30...ool-motor.html

I am thinking about running it in a 17" ABS mini hydro I have.

I was going to run a 4800kv motor http://www.hobbypartz.com/07e-c-sl-12t-2040-blue.html
but figured the 3000kv would be a little better
going to run it with a hobbywing 35amp esc any thoughts?

Hobbyking just started selling similar motors; a 300W http://www.hobbyking.com/hobbyking/s...dProduct=11875 and a 400W http://www.hobbyking.com/hobbyking/s...dProduct=14622 both 3000kv. Look to be very promising!

[martin]

Your better off going with one of the various 450 size outrunners, Much more powerfull motors, But you may need a higher amp esc. Heres a 450 size outrunner in my 15" mono deep v that cost around $12 + shipping for the motor. Martin.


http://www.youtube.com/watch?v=qzNAdNICzWg
http://www.youtube.com/watch?v=-zYKfxjOJ1A

[Meniscus]

There's tons of Inrunners to choose from. On the Outrunner side of things, I've run the Etti 2217 (3600kv) and the Scorpion HKII-2208-24 (3590kv). Both have performed very well without issues. Both motors are around 28mm diameter. Several seasoned racers in Europe use the Etti outrunners with great success.

For example, Walter Geens set several records in NAVIGA oval using the Etti on 3s and a 90A ESC in a 73cm model. Yes that's just shy of 29"! He was measured doing around 70mph on the straights in oval trim.

With the outrunners, just be sure to confirm the amps they handle. Many will not handle the amp load we see in boats.

Hope this helps.

[martin]

I have 3 Etti 3600kv outrunners & their very good motors & was using them in the little 15" mono that ive just posted youtube footage of in the post above. The motor used in the footage is the next step on using a 3800kv outrunner that cost $12 & its faster than the Etti motor. In actuall fact the motor that Etti sell is just a 450 heli motor (the gold anodised one). I get that same motor from a HK Ebay seller also for $12, Its just an unbranded 450 motor but its the same motor, I now because i bought one just out of curiosity & took it apart to compare & its the same motor inside as well. Put it in the boat & speed & performance is the same as well.Martin.

[Alexgar]

ive been eyeballing this
http://www.hobbyking.com/hobbyking/s...dProduct=11179
those watercooled inrunners seem expensive considering there low output specs

[Meniscus]

ive been eyeballing this
http://www.hobbyking.com/hobbyking/s...dProduct=11179
those watercooled inrunners seem expensive considering there low output specs

At 600 watts, I'm not sure those wires would hold up, but I could be wrong. For smaller setups, I'd imagine it would be OK.

[sundog]

Wow, talk about synchronicity. I just got back from running a modded 17" Tear-Into jet sprint with that motor. 2200mAH 3s Turnigy, 60A esc and that boat hauled. No supplemental cooling for the motor and it was cool to the touch after about 8-10 minutes (but then, the river was cold)! The battery and (watercooled) esc were just warm to the touch. I had been having trouble with the boat porpoising on WOT, so was trying out a new ride plate I made for it. I'm quite happy with this motor so far.

[monojeff]

ive been eyeballing this
http://www.hobbyking.com/hobbyking/s...dProduct=11179
those watercooled inrunners seem expensive considering there low output specs

I was looking at this motor also debating between it & the outrunner I posted.
This one seems would need a bigger esc & puts out more power.

Similar to the outrunner they used in the mini jae http://www.hobbyking.com/hobbyking/s...dProduct=11177

Just not sure as the hull I have is ABS I really don't want any heat build up & since it's so small it's not gonna take much to make it go.
I think less power might be a good thing. But I am still learning....